Topeak Defender M2 £17.99

Topeak’s dual cam quick-release comes with a set of yellow shims to accommodate a wide variety of seatpost sizes and, while the QR means the M1 can be removed if you want to pack your bike into a car, we found it can get knocked off line easily. The M2 is a little narrower than a Crud Guard but it gets a rubber tip that will bend rather than break and has overall better construction and fittings. These get gummed up in time and the M2 does weigh a fair bit but it’s the best Topeak guard to date.